1981 fiat spider 2000 fuel injection trouble

[launieg]

To answer your last question and repeat what others have said, the injectors get the ground side through the ECU, as has been stated, and they get the positive side from the double relay, but again as permitted by the ECU! So the ECU ultimately controls both sides of the circuit.

It's another "hit or miss" attempt, but using Brad Artigue's FI Guide you might want to check the throttle position sensor (TPS). It's an easy check and be sure to also check its plug (both the male and female ends) and wires too. The TPS can tell the ECU to stop firing the injectors. (The TPS is right where you would expect it to be - on the side of the throttle.)

Don't take your car to anyone who does not work on Fiat Spiders. They will waste your money on this problem.

If you ultimately need to swap-test your ECU, let me know and I'll lend you one.

I've been where you are on this , and you will succeed.

[pope]

I agree with Ron.
The fat Brown wire is what powers the ECU and the injectors. The injectors get their power, independent of the ECU. When you turn the ignition on, the pink/white wire energizes the relay and allows the two brown wires to flow through the relay.

The brown w/white wire is what powers the fuel pump. Make sure you put a 16A fuse in the holder you installed.

Another thing to quickly check is that the grounding cable from the frame to the transmission bell housing is intact. If there is none, install a jumper cable temporarily from the engine to the body for all these testing procedures. Fuel injection harness grounds to engine,

We are trying our best but with out being there and not seeing the overall condition, there could be something else effecting things that we are not aware of.

[macawlover70]

well guys, I bought my relay from ebay and it is gauranteed to work but when I hook up the side with all the power wires(Brown/white,Brown, red/black) which all work, the only power coming of the other side is 12 volts from 85. All the rest are dead, no power. With or without it being hooked up to the ecu. So, my question is does that mean the relay is not good. I need to know if I am getting power everywhere I should into the relay then if the relay is good I should get power to 88b and 88e regardless of the ecu if the relay is gopod. Correct?

[rlux4]

Check that the large connector on the back of the ECU is plugged in securely.
Launie's offer of the ECU is something to consider. I also have one that I could loan you to test if yours is the problem if shipping accross the border is an issue.
Ron

[launieg]

Well, without refreshing my memory, I respectfully disagree - I am reasonably sure that the ECU has a line to the relay that (when the ECU allows it) completes a circuit inside the relay that activates the positive connection from the ignition input on the relay to the injectors. So if the ECU is not connected or is not "sending that signal" to the relay, then you will not have power at the injectors. I think I recall that it is terminal 28 on the ECU that sends that signal to the relay. So you need the ECU connected, working, and receiving the appropriate messages from sensors that will permit the relay to function in respect to the injectors.

On the other hand, it has been a while since I played with my car, and I could be wrong

[macawlover70]

Hey guys. In the diagnostic manual the first step when not getting power to the injectors is to test 88z and 85. If the light doesn't work test it to 88z and ground. This led me to believe that 85 was a ground. And maybe it is but I am getting 12 volts from 88z(big brown) and 85(small white to ecu) I don't think thats right.
And to make matters more complex I took apart my 1st relay and there are two switches inside. One on each side. When I manually switch the side going to the ecu I do get the correct voltage at 88b and 88e. So I tried to start it. Nada. Then I went to test the voltage with the noid tester and couldn't find it so I quit for the day. I think both relays are bad. I think when the key is turned on it is supposed to activate the switch, which it is not.
I thank you for the offer of the ecu's guys but I'm afraid unless I know my connections and voltage are correct I'm afriad of frying someones ECU. So maybe not a good Idea. I think I will start looking for a good fiat mechanic in Corpus Christi,TX on Monday.
Thoughts?

[rlux4]

To let everyone know, I have offered to solve this problem. All I'm waiting for is the car on a trailer being pulled into my place.
I think you're right Launie, the dual relay will need the voltage from the ECU to trigger that side of it so the 88 b & e terminals will have power. We've always been under the impression that the ECU is pretty bullet proof, but that's not to say that they can't go bad. I would be suprised to learn that a new dual relay was defective, so it could be the ECU. I would suggest again that a 250-300 ohm resistor be put in the connector on the temp sensor in the coolant "T" if you haven't already. This sensor is the one that could cause a no start problem, and the resistor will replace it in the loop. It could be either a bad ECU, or, more probably, something is not being satisfied for it to complete the hot circuit to the injectors.
Macawlover and I are communicating to see about getting him my spare ECU and dual relay.
Ron

[bwilson27]

It is basically because of things like this that I'm glad I have a carb.
They may not be as advanced, but the simplicity is worth it.

[pope]

good luck guys

[launieg]

I hope I'm not sounding condescending, but It's important to remember that FI is a single integrated system. I would start completely over by confirming that you have spark at the plugs and fuel pressure at the injectors. Then go through each and every sensor in the FI system, check each plug to each sensor, and then check the continuity in the wires to each item. Get all of that working properly. Don't go looking for your problem - just get each component working properly. Check out every item in Artigue's guide, and only then try replacing the ECU.

I found that it's amazing how I can get stuck on looking at the wrong item and ignoring everything else. I've spent days hung up on what I thought was the problem area, only to find it was something I had assumed or decided was okay and therefore hadn't checked out thoroughly.

FI can certainly be a pain to diagnose, but when cleaned up it is very reliable. I like it a lot.

[drr3755]

My son just bought a 1982 fiat spider 2000 . Been reading you post will check the problems you have with the wireing .
the one im workin on is not fireing the the noid light till you let off the key as it come off start position. Cleaned the gas tank , new pump, filter Got good pressure at injectors IM a Journeyman Skilled trade Millwright. A parterner in a Auto and Truck repair shop (KENS AUTO AND TRUCK REPAIR complete automotive service) OFFICE 769 257 5638 We have Alldata for all make and models BUT I can't pull up hardley any information on this car GOT more info just from your post than I've had in days THANK YOU ALL..

[Divers]

I realize I am digging up a very old post, but this one should have a special place for troubleshooting!


I was looking for an ending to this story.....in the end what fixed this issue.....Ron??

[rlux4]

Yes, I sent him my spare ECU and it did the job. He used it until he found a replacement and sent it back to me. He also sent the bad one and I've had it apart to get an idea of how they're put together. One of these days Id like to try to diagnose what the problem with it is, but it's a project that I don't seem to find the time for so far.
Daniel no longer has the car, but we still talk every once in a while. Another friend I made because of the Fiat Spider.
Ron

[Divers]

Thanks Ron. I am going to use this thread to troubleshoot my current problem.

Thanks again for this post.

Robert